Ilona was born in Vienna in 1915. Her mother, Marie Kozuschníková, an ethnic German/Catholic Czech, was not married to her father, Artur Neumann, a secular Czech Jew. Christened immediately after birth, she was adopted by her father and became Ilona Neumannová. She fell in love with Rudolph Heller, and they were married in 1934. Their only child, Ota, was born in 1936. After the occupation, Rudolph escaped to join the British Army, and Ilona, Gustav, and Ota were taken in by farmers. Prior to being taken to a labor camp, Ilona hid her son on a farm. Rudolph, Ilona, and Ota were the only survivors of the war. In 1948, they escaped from the Communists, spent 15 months in DP camps, and arrived in America in 1949. ​